St John sent one rapid response unit, one manager and one ambulance. They treated and then transported one patient in a serious condition to Christchurch Hospital, a spokeswoman said.
The Armed Offenders Squad (AOS) rushed to the scene.
Police this afternoon confirmed no arrests have been made and say they are now in the early stages of an investigation.
"We appreciate a firearms incident on a suburban street will have caused anxiety for our local community," said Detective Senior Sergeant Tania Jellyman.
"The community will notice an increase in patrols in the area."
Police have taped off a property at the corner of Stanmore Rd and Hereford St.
The police say cordons are in place while they work out what has happened.
Parents with children at a daycare in the area have been told the centre has been locked down.
The pre-schoolers have been taken indoors on the advice of police.
A local told the Herald that police are often in the area.
"The gangs are taking over and they don't seem to care," he said.
"It's worrying because there are a lot of genuine, decent people around and it's just a minority that is doing all the damage."
Police are asking for witnesses or anyone with information or concerns to call 105 - quoting file number 220830/8157 or anonymously via Crime Stoppers on 0800 555 111 or www.crimestoppers-nz.org.